ARUSHA, Tanzania, April 4 (Xinhua) -- Tanzania Immigration Services Department (TISD) said it has arrested 40 illegal migrants from six African countries.

Paul Eranga, Mwanza Region Immigration Officer, said Wednesday that the aliens are from Kenya, Uganda, Burundi, Ethiopia, Nigeria and the Democratic Republic of the Congo (DRC).

Eranga said the illegal immigrants were arrested following a special operation by TISD in collaboration with police between March 28 and April 3 in the Lake Zone region of Mwanza.

He said during the security operation they arrested the illegal migrants including 14 Kenyans who were working with a local music group without proper documents. He said the music band is led by a Kenyan national, Moreen Achieng.

"They illegally crossed into Tanzania to perform music shows during Easter holidays without having travel documents and work permits," he said.

According to Eranga, on March 29, they arrested other illegal migrants from Uganda, Ethiopia, Burundi, Nigeria and DRC.

The immigrants are said to be using Tanzania as their transit route to South Africa or European countries.

Tanzania's authorities have blamed the vastness of the region for the runaway influx of foreigners into Tanzania through porous borders.

Refugee rights organizations and aid agencies have blamed poverty in Africa for the rising cases of human trafficking.